Due to the fast indiscriminate increase of digital data, data reduction has acquired increasing concentration and became a popular approach in large-scale storage systems. One of the most effective approaches for data reduction is Data Deduplication technique in which the redundant data at the file or sub-file level is detected and identifies by using a hash algorithm. Data Deduplication showed that it was much more efficient than the conventional compression technique in largescale storage systems in terms of space reduction. Two Threshold Two Divisor (TTTD) chunking algorithm is one of the popular chunking algorithm used in deduplication. This algorithm needs time and many system resources to compute its chunk boundary. This paper presents new techniques to enhance TTTD chunking algorithm using a new fingerprint function, a multi-level hashing and matching technique, new indexing technique to store the Metadata. These new techniques consist of four hashing algorithm to solve the collision problem and adding a new chunk condition to the TTTD chunking conditions in order to increase the number of the small chunks which leads to increasing the Deduplication Ratio. This enhancement improves the Deduplication Ratio produced by TTTD algorithm and reduces the system resources needed by this algorithm. The proposed algorithm is tested in terms of Deduplication Ratio, execution time, and Metadata size.

Android operating system, since its first start, is growing very fast and takes a large space in smart devices market. It is built and developed on Linux and designed basically for touch screen devices such as, mobiles, tablets, etc. Mobile devices are markedly complicated and feature-rich; therefore they are prone to reliability of software and performance problems. Because of the small resources, smart devices, such as CPU, RAM, suffer from problems. One of these problems is Software Aging (SA). SA is recognized in long running OSs as a shortage in resources, performance retreating, and finally failure. SA is looked at from two sides, namely the poor response time of application which represents the end user side and the shortage in metrics related to device resources, such as RAM and storage. In this paper, a set of eight experiments is conducted to distinguish SA in Android mobiles. These experiments are conducted to find the correlation between Launch Time (LT) with RAM and storage metrics covered in this paper. Statistical methods, such as Mann Kendall test, Sen’s slope, Spearman rank correlation, and Design of Experiment (DOE) are used to prove the correlation statistically. These experiments assist to detect SA, which will be helpful in the rejuvenation strategy of applications.

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Android OS is developing very fast, and because of being an open source OS, it is vulnerable to many problems that are manifested to users directly or indirectly. Poor application launch time is one of these problems. In this paper, a set of sixteen experiments is established to distinguish the factors that have the most evident effects on application launch time in Android mobiles. These factors are application, launch and kill, events, and storage. Mann Kendall (MK) test, one way analysis of variance (ANOVA), and Design of Experiment (DOE) are used to prove the influence of factors statistically. As a result of the experiments, the application factor, especially the third party applications level, has the most prominent effects on application launch time, followed by launch and Kill and events, while storage had the least influence.

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